过零双门限协作频谱感知算法

(1.国家无线电监测中心 乌鲁木齐监测站,新疆 乌鲁木齐 830054; 2.国家无线电监测中心,北京 100037)

认知无线电; 频谱感知; 过零双门限协作频谱感知; 过零检测; 噪声不确定性

Zero-crossing dual-threshold cooperativespectrum sensing algorithm
XU Guo-qiang1,WANG Meng1,LI Ying-hua2,KANG Pei-chuan2,BAO Yao2,YANG Wen-han2

(1.Urumqi Station,The State Radio Monitoring Center,Urumqi 830054,China; 2.The State Radio Monitoring Center,Beijing 100037,China

cognitive radio; spectrum sensing; zero-crossing dual-threshold cooperative spectrum sensing; zero-crossings; noise uncertainty

DOI: 10.13800/j.cnki.xakjdxxb.2019.0121

备注

应用过零双门限协作频谱感知算法估计无线电频谱的占用状态,研究了认知用户个数、计算所用的采样点数、不同信噪比及判决系数对检测概率的影响,并与传统双门限能量检测、差分双门限能量检测算法的检测性能进行了对比研究,发现在信噪比为-5 dB,判决系数为0.05,虚警概率小于等于0.8时,过零双门限检测方法单认知用户检测性能明显优于其他2种检测方法; 当信噪比均为-5 dB,参与协作感知的认知用户个数小于6时,过零双门限协作检测算法性能明显优于其他2种算法; 在虚警概率恒定的情况下,增加计算所用的采样点数或增大判决系数能够明显提高检测概率; 在虚警概率恒定情况下,算法检测概率随着信噪比增大而增大,当信噪比为-7 dB时,检测概率趋近于1; 在相同的检测条件下,过零双门限协作检测算法的虚警概率要明显低于差分双门限检测的虚警概率。结果 表明:过零双门限协作频谱感知算法可以降低系统的虚警概率,有效解决噪声不确定性问题,进一步提高系统感知性能。

The occupation state was studied in radio spectrum by zero-crossing dual-threshold cooperative spectrum sensing algorithm.The effect of the number of cognitive users,the number of sampling points used in the calculation,the different signal-to-noise ratio,and the decision coefficient on the probability of detection was studied.The detection performance of the algorithm was compared with the conventional dual-threshold energy detection algorithm and dual-threshold spectrum sensing algorithm based on differential energy detection.It is found that when the signal-to-noise ratio is -5dB,the decision coefficient is 0.05,and the false alarm probability is less than or equal to 0.8,the single-user detection performance of the zero-crossing dual-threshold detection method is obviously better than that of other two detection algorithms.When the signal-to-noise ratio is -5 dB and the number of cognitive users participating in cooperative sensing is less than 6,the performance of the zero-crossing dual-threshold detection algorithm is obviously better than that of other two algorithms.When the false alarm probability is constant,increasing the number of sampling points used in the calculation or increasing the decision coefficient can significantly increase the detection probability.When the false alarm probability is constant,the detection probability of the algorithm increases with the increase of SNR; when the SNR is -7 dB,the detection probability approaches 1.Under the same detection conditions,the false alarm probability of the zero-crossing dual-threshold cooperative detection algorithm is obviously lower than the false alarm probability of the dual-threshold spectrum sensing algorithm based on differential energy detection.The results indicate that zero-crossing dual-threshold cooperative spectrum sensing algorithm can reduce the false alarm probability of the system,effectively solve the problem of noise uncertainty,and further improve the system's perceived performance.